Ball track set



FIG. 1 is a perspective view of a ball track set, showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a back elevation view thereof; and,

FIG. 6 is a top plan view thereof.

The views of the ball track set not shown form no part of the claimed design. The details shown in broken lines are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a ball track set, as shown and described. 